Multibeam head lamp incorporating gradually fluted reflector and pluraality of filaments



1951 H. COULTER 2,565,757

MULTIBEAM HEADLA INCORPORATING GRADUALLY FLUTED REFLECTOR AND PLURALITYOF FILAMENTS Filed June 5, 1946 5 Sheets-Sheet l IN VEN TOR.

G. H. COULTER Aug. 28, 1951 2,565,757 MULTIBEAM HEADLAMP INCORPORATINGGRADUALLY FLUTED REFLECTOR AND PLURALITY OF FILAMENTS 5 Sheets-Sheet 2Filed June 5, 1946 Jig, ]ZZZ INVENTOR.

1951 G. H. COULTE 2,565,757

R MULTI AM HEADLAMP I C RPOR GRADU LY FLUTED 1 EFLECTOR AND URALI FILAFiled June 5, 1946 NTS 5 Sheets-Sheet 5 INVENTOR.

- 2,565,757 GRADUALLY FLUTED FILAMENTS 5 Sheets-Sheet 4 Allg- 1951 G. H.COULTER MULTIBEAM HEADLAMP INCORPORATING REFLECTOR AND PLURALITY OFFiled June 5, 1946 Que/HM 1951 H. COULTER 2,565,757

MULTIBEAM HEADLA INCORPORATING GRADUALLY FLUTED REFLECTOR AND PLURALITYOF FILAMENTS Filed June 5, 1946 5 Sheets-Sheet 5 INVENTOR W EW PatentedAug. 28, 1951 .MULTIBEAM HEAD LAMP INCORPORATING GR-ADUALLY "FLUTEDREFLECTOR AND PB IJR ALITY OF FILAMENTS ;Guy%l-l.;oulter, Detroit, Mich,assignor, by mesne assignments, to The Electric Auto-Lite Comgpany,.T0led0, Ohio, alcorporationof Ohio Applicationalune 5, 1946, Serial No.674,441

-16 Claims.

This invention relates :to automobile :head- .lamps and has for itsobje'ct the provision. ofa-an improved headlamp construction :of lthetwo 1131- 'ament type, in which ine overallefiieiency in :illuminationis increased andxaadesirable beam pattern for both the drivingrbeamswand'passing :beams is obtained.

One of therobjectsrof 1the':present.-.invention is 'to providea.headlampiiinWhich1the frontcover glass. may be ofplaininonstructionrand in @which the control of the beam patterniszobtain'ed by a .novel arrangement or :projecting .isurfaces 011 theconcave reflector forming the back portion of the headlamp thusproviding -a=.simplified;t oe iof front cover. The kplainiglass absorbs:much lesser the transmittediiightffhu; :that 'is otherwise the :casewhere -:-fiutes an'd :prisms are required.

:ent invention to provide a .series :of modified paraboloidal rearreflectingrsurfaces to produce a beam pattern;inwvhichttheilightffiuxvis 'generally .:concentrated to egive good driving achar- 'acteristics:while :at'the same time maybe laterally extended :dependingzon .thevariations in the :reflecting "surfaces which I provide. Not only do Iprovidetaseriesiof verticallyarranged concavereflecting:surfaces sorelated to the: filaxmentiposition ;as:to produc.e :a :certainparal-leliz- :ing eefiect of the light eraysfbut one xin which" theseveral. sections :may be; also curved "convexly and 'concavely viewedin =aatransverse manner where- 'by 1am able toveryzaccuratelyeontrol'the make :up'of the beam'patternand the projection of the"total, light flux.

A still further :object :of the present invention is :to provide :aheadlight construction of the character indicated in "which additionalfilaxments and controls :itherefor are vemployed for ":producing thecorrectjlight projection whenithe automobile is turning on a right handturn-for example, orrtothe leftthand and one in which in :conjunctiontherewith when the automobile is :being driven straight ahea'd, iscapable-oi producing a long distance dri-ving beam of the characterindicated above and a passing beam thrown downwardly and'toward theright hand side of the road.

i'Furtherobjects 'and advantages are within the scope oi'' thisinvention suchfias relate to arrangement, operationcandifunctionioi therelated elements of the structure, toyari'ous "detailsnf construction.andto combinations of parts, elements per se, and to economies :ofmanufacture :and numerous other features :as will be apparent from aconsideration :01 the specification rand drawing of a form:ofcthezinvention, which'may be preferred, in which:

Figure I, issa front velevational aview :of "one ;embodiment of :myinvention;

Figure II is a vertical sectional diagrammatic view showing the'trueparabolai-infdottedlines to illustrate the configuration 'iOf'thezrefiector;

Figure III isua verticalzsectionaliviewtakenion theline III-.IIIoffFigurel;

FigureVIV is a horizontalsectional view'taken on the line IVIV:of.Figurefl;

Figure I-a. is a modification ofizthe embodiment of Figure I "which:means are provided for projecting certain;rayst' to ;the :righton'ly;

Figure 1-1) isla diagrammatic View? illustrating the operation of theembodimentsofiFigure 1-11.

Figure V is alfrontwelevationalFview ,ofcanother embodiment of .myinvention;

Figure VI is ;a' verticalsectional :view on the line VIVI of Figure V;

Figure VII is a horizontalisectional'viewtaken on the line VII- VII ofFigure-V;

Figure VIII is a front elevational -view of another embodimentr of.my.invention;

Figure IX is a verticahsectional view-taken on the line IXIX7of.FigureVIII; while Figures X and'XIare h'orizontal sectional views taken onthelines X;X and1iXI-iXIof Figure VIII;

Figure XII is a3frontelevational view ofan embodiment of myrinventionshowingimeans to facilitate projecting .proper rbeams for turning curvesto :tharighthand or the left hand;

Figure 'XIII is :a horizontal sectional view on line XIIIXIIIlof' Figure"XII;

While Figure XIV is a-sectional view showing the filaments used thisembodiment of 'my invention;

Figure XV is a front elevational view of-a still further embodiment ofmy-invention illustrating the use of the headlamp-as a bulb, in itself,without the need of a separate miniature bulb;

Figure XVI is 'a'vertical sectional view ofFigure'XV;

FigureXVII isa cross section on-lineXVIL- XVII of Figure XV;

Figure XVIII is a diagrammatieview of the model of Figure XV.

Referring-to the embodiment of'my invention illustratedin Figures'I'through'IV, I have here illustrated a concave glass-rflector I0having a plurality of vertical concave flutes ll, molded into the glassreflector and provided on its front face with *a suitable light*re'fiecting *surface l 2 which may be an aluminized reflecting coatingor a silvered reflector.

The front cover I3 of my headlight is of plain glass and the absorptionof light flux is greatly reduced. This cover I3 may be suitablyconnected to the reflector It by metallic or suitable cementingcompounds.

Each of the vertical concave flutes II extend in a substantiallycontinuous curvature from the top of the reflector In to the bottomthereof. As shown in Figure II the top of each flute II is bentdownwardly from the true parabola illustrated in dot and dash lines,whiie at the bottom, the lower terminal of each flute is depressed belowthe true parabola position as likewise shown in Figure II. While I haveshown each flute II as vertically arranged and one parallel to theother, I intend in certain embodiments of my invention to dispose theseflutes angularly with respect to the vertical but properly correlated tothe focus of each flute, the locus of the foci being in the mean centerof all the flutes used.

Two bar shaped filaments I4 and I5 are employed, the main filament I4being located at focus or the locus of the foci of the several verticalflutes I3 and the other filament I5 offset both vertically andhorizontally. The beam projected when the main filament I4 is energized,I refer to as the main driving beam for the motor vehicle and theheadlamp projects a long distance symmetrical or slightly asymmetricalbeam far down the roadway but laterally spread toward each side of theroad to make an ideal country driving beam. This lateral spread isobtained by the transverse curvature given to each of the verticalflutes II. .In Figure IV I have designated several of these flutes as A,B, C, D, etcetera. In practice, in the horizontal plane passing throughthe main filament I4, the curvature of the flute is so flattened out asto conform substantially to the true parabola in the zone as illustratedin Figure II. Considering a point vertically from the center of flute A,for example, where the first line is indicated on Figure I, I provide alateral spread of 3 or 4 degrees by giving the flute at this pointsuflicient transverse curvature to attain this amount of spread. Igradually increase the arc of transverse curvature of the flute A as Iapproach the top portion of the headlamp so that at the top I provide atransverse spread of from 40 to 42 degrees. Considering the lower halfof one of the flutes II, as indicated at A, I accomplish substantiallythe same effect by giving the flute sufficient transverse curvature nearthe central zone as to spread the light from 3 to 4 degrees andcontinuously and gradually increase the transverse curvature of theflute to consequently increase the spreading power of the lightreflected therefrom to approach 40 to 42 degrees at the bottom centralportion of flute A.

I locate the other filament l5 offset from the vertical axis of thereflector as well as located above the horizontal plane so as to projecta beam of light from the filament I5 downwardly and toward the righthand side of the road viewed from the drivers seat. This means that thefilament I5 is offset to the right looking into the headlight as inFigure I. Both filaments I4 and I5 are located as nearly aspossible inwhat may be termed the focal plane of the reflector, or what would bethe nearest to the focal plane of the several vertical sections I Iillustrated in this embodiment of my invention.

As will hereinafter more fully appear, the vertical modification of theflutes from th U 6 parabola, as illustrated in Figure II, has the effectof throwing the light downwardly, whereas the transverse curvature tothe individual flutes as illustrated in the sectional view of Figure IVas well as indicated in Figures I and III is for the purpose ofspreading the light laterally.

The special location of the filament I5 not only throws the beamdownwardly but directs it laterally to the right side of the road.However, some of the light, according to the optical law in relation toa parabola, particularly that in front of the focal plane emanating fromthe upper filament I5, instead of passing to the right is directedtoward the left. An important feature of my invention is a correctivearrangement for this feature and is illustrated in'Figure I where it isseen that the flutes disappear at the. central zone which fans out onboth sides from the central part as indicated at X and Y. By eliminatingthe spreading effect at these particular sections, I have found that itis possible to get the overall desired beam pattern in which, while someof the light is thrown to the left, the omission of spreading flutes atthese points X and Y cuts oif the additional spread which wouldotherwise occur. In this way I obtain the desired beam pattern with thesubstantial effect of throwing the effective passing beam down and tothe right as desired.

In Figure I-a, I shown means for projecting rays emitted by the offsetfilament I5 and contacting the reflector in front of the focal planealso toward the right hand side of the road viewed from the driversseat. According to the law of optics certain rays issuing from suchfilament I5 and contacting certain portions such as X and Y of anunmodified parabolic reflector, instead of being reflected toward theright would be projected toward the'left. In Figure 1-11. at thesesections corresponding to X and Y of Figure I, I have provided a seriesof specially constructed flutes I6 in which a curved transverselyconcaved surface I! projects rays from the filament I5 to the right andnone or substantially none to the left so that the combined light fluxreflected from these sections X and Y is added to the light projectedtoward the right following the inherent laws of optics from thereflector at that portion located at the rear of the focal plane andemanating from the offset filament I5.

These flutesIG are curved vertically on the contours of the slightlymodified parabola as shown in Figure II. It will be noted thattransversely these surfaces II, instead of being curved one half to theright and the other half to the left as in Figures I-IV (see Figure IV),as shown in Figure 1-11, these surfaces I! are curved all in onedirection as a continuous curve. In Figure 1-11, I have showndiagrammatically the projection of the rays from the curved surfaces I!at the portions X and Y of Figure I-a to be reflected by these speciallyconstructed flutes I6. Instead of making these flutes I! concaved theymay be provided with plane surfaces or properly arranged convexreflecting surfaces at these sections.

Otherwise, the headlight of Figure I-a may be made as in the severalother embodiments of my inventions herein illustrated not only in FigureI but in the other additional modifications hereof as well.

In the embodiment illustrated in Figures V, VI, and VII, I employ theconcave reflector II], vertical flutes I I, reflecting surface I2, andcooperatng filam nts I4 and I5. as in. the embodiment of FiguresI-through IV-;- In the ,embodimentof-Fig: ure V, however, each of thevertical flutes .I l, instead of-being ona continuous curvaturevertically, is made up ofa plurality ofdndependently designed flutesections illustrated at 20, 21, 22-, 2'3, and-2A, for example, foronelof thepcentral flutes I I. Each of these individual sections hasavarying degree of spreading, and bending'power. For example, the sectionZIIjprovides very, little spreadT-from to 4 or 5 degrees, Section} [hasmore spreading :power, while .section.22; may, have a spread of from todegrees. iTheatop sec-: tion 24 of the central flute mayhaye as high aspread as from to degrees.

The, lower. vertical half. or section of the reflector is substantiallya duplicate of the upper section withthe bending and spreading powerincreasing from the central section. 20 of the flute toward the sectionssuch as 24' at thelower rim.v In both the upper and lower half, I varythe arrangement and instead of having-each successive section as viewedfrom i the center toward the outer rim, increasing. inuspreadingorbending power, somesections may increase and others decrease comparedto the next adjoining section both above and below sothat Ican readilyproducethe-most desired configurationzof the light beam patternprojected by the headlamp.

It will benoted that I provide the unmodified parabolic sections fannedout as at X- and Y, similarto the arrangementillustrated in theembodiment of my Figures I to IV'forthesame purpose referred to supra inconnection with that embodiment.

In the embodiment of my invention, illustrated in Figures- VIII to XI, Iemploy inthe upper half of the reflector a series-of convexly curvedflutes in transverse configuration, while on-the lower half the flutesare reversed and made concave as in the embodiment of Figure-I.- Thus,inFigure VIII the upper half of the flute 3U-is convexly shaped asindicated at-the high-spot or-line as at 3| in Figure-X. In this-casethe vertical configuration of each flute 39, as shown by Figure X, isnot modified from the true parabola at its lateral base edges 32 and 33(Figure VIII). However, the central-highportion or zone-3I in the upperhalfof thei-reflector-has the same effect in modifying the downwardbending power as compared with the true parabola, and I obtain resultssimilar atthis particular line to the modification illustrated-am FigureII of. the embodiment of Figures I to .IV; The spread laterally isobtained--by.the.transverse convex configuration of the flute. Again adownward'bending efi'ect-is also obtained in the lower half of thereflector in Figure VIII since by changing from a-convex-flute-SD at theupper half .to-aconcave-flute H at the-r-lowenl-half (similar to thelower half of Figure .I), the result produced is similar to thatobtained by drawing down of the reflector from the 'true parabola asindicated in the lowerhalfl of Figure II.-..

It willbe seen from Figure VIII. that I provide inthis embodiment thesections .X and- Y-asin the other embodiments to prevent animproperdirection of certain-of the rays too far to-the left, which wouldotherwisebeathe case were the Spreading flutes included inthesearrangements.

In Figures VIII-XI,- I changethe arrangement of filaments I4 and I5andplace the main filament. slightly. below the horizontal transverseaxis through the focus, but located with the center of the filament onthe central vertical 6 axis; through theisfocus. The.-;-.other:filament}: I 5 is: located! offset both, vertically and horizontally,substantially as in the; other embodiments.

In the -embodiment,illustratedin Figure; XII, XIII and XIV, I employ twoadditional :sepe arately, energizable filaments,- 49' and: 4 I which areconnected by-the operator with a source of energy when-theymotor vehicleis turning to the right-hand or tothe, left hand. Otherwise, in thisembodiment; I- utilize substantially the same type: ofhead'lampillustrated in the: embodiment of -Figures VIII-to- XI-witlrthe.reflector-1 I 0-, flutes IA' and: 39, with, the'twostraight, awaydriving beam filaments, thermain' filaments I 4, however, beingzIGCfigllCdpEtS: nearly; exactly at :focus. as is possible, while thefilament-I5 is, offset vertically and horizontally-tothrow. the lighttoward. the righthand: of=the side of.- the road as in,.;the embodiment,of FiguIeVII Ii: Moreover, as shown, -the,---fiut es II; areformedcancave at the-bottom as at A in-Figure. VII-I, and-convexed atthe top as particularly illustrated in Figure X.

It. will ibe understood that in-this: embodiment forenormal driving,the. main filament ldvforms the. source ,optheillumination for themaimdriving beami When passing ;other, vehiclesgthefila: ment;I,5,-isenergized-which; throws the .;-light; as, heretofore stated,downwardly; and toward the: right hand (side; ofthe. road. .However,when it is-desired to turn toward the, righthand; the filament-Allisalsoenergized andthis throws a substantial amountofilight toward the,right as the vehicle begins-to turn "and greatlyfacilitates 'righ-t,hand turning. On the: other hand; if it, is.- desiredto turn: toitheleft, the other.- fila: mental is energized andiilikewisegtheibeampatetern, having alarge-amount, ,of :light; distributed toward the. left.is; produced to facilitate. left hand turning.

Inrthe embodiment illustrated in- FiguresXV; XVI; XVII, andXVIII, theoptical. arrangement of .theheadlamp issubstantially a duplicate of thatillustratedin Figuresv I through IV, except:- in ithat insteadof using aminiature bulb, as illustrated in -Figures I andIII, the entire-headlamp contained within the space formed by the concave reflector I I).and front coverglass I3 constitutes thevacuumspace or gas filled spacewithin whichthe several filaments I4 and. I5. are located and :connectedwith suitable lead in connectorslfi, I1, and I8, as shown. In thisinstance it will ,be understood that the front cover I3. isherm-eticallysealed at-IS to the rim of the re-' fiector III. Inthisxembodiment I also show in Figure: XVIII how they vertical flutes II are con tinuously. curvedxon-ia modification of the true parabola, thelatter. being indicated in'Figure XVIIIin-the-dottedlines;

I also use a sealed beam type of headlamp in the embodiments of FiguresV through VII instead of'employingthe miniature bulb there illustrated.

Itisunderstood that the reflector in the several embodiments may-be madeof glass or a plastic composition, with the reflecting surface I2supplied thereto, andlin the embodiment of Figures I, V, VIIIand XII theconcave reflector l0 may be. made of metal suitably provided with. apolished eflectin -front surface I2.

It is apparent that Within the scope of this invention;modifications-and, diiferent arrangements may be made-other thanisherein disclosed, and thepresent: disclosure is illustrative merely; theinvention comprehending all variations thereof:

WhatsI- claim iS-ilzi 1. In a headlight, the combination of a concavereflector; said reflector comprisin a plurality of individual sections,and a plurality of horizontally arranged filaments, one located substantially at the focus and symmetrically disposed with respect thereto; theother filament being horizontally but laterally and Vertically offsetfrom the focus to project a passing beam downwardly and to the righthand side of the road; a substantially transparent front cover plate forsaid headlight; and means to connect said front cover and saidreflector; each section of said reflector comprising horizontally curvedflutes, the lateral edge of each flute conforming substantial- 1y to aparabola and the central portions modified from the parabola in varyingamounts vertically and horizontally from the upper and lower edges ofthe reflector to the central zone area thereof where the flutesgradually flatten out to conform substantially to the true paraboliccentral zone without forming abrupt transition surfaces.

2. In headlight, the combination of a concave reflecting surface, saidreflector comprising a plurality of vertical individual sections, eachsection being vertically curved to form a convex flute at its upperportion and transversely curved to form a concave flute at its lowerportion, each section being vertically modified from a parabolic contourin variable amounts from the upper and lower edges of the reflectortoward the central area thereof without forming abrupt terminalintersection surfaces so as to project light downwardly and laterally; aplurality of horizontally arranged elongated filaments, one locatedsubstantially at the focus and symmetrically disposed with respectthereto; the other filament being horizontally elongated but laterallyand vertically offset from the focus to project a, passing beamdownwardly and to the right hand side of the road; a substantiallytransparent front cover plate for said headlight; and means to connectsaid front cover and said reflector.

3. In a headlight, the combination of a con-=- cave reflecting surface,said reflector comprising a plurality of vertical individual sections,each section being vertically curved to form a convex flute at its upperportion and transversely curved to form a concave flute at its lowerportion, the transverse curvature of said convex and concave sectionscontinuously varying from the bottom and top portions to the centralzone of said reflector whereby each section is modified vertically andhorizontally from a parabolic contour from the upper and lower edges ofthe reflector toward the central area thereof without forming abruptintersection surfaces so as to project light downwardly and laterally; aplurality of horizontally arranged elongated filaments, one locatedsubstantially at the focus and symmetrically disposed with respectthereto; the other filament being horizontally elongated but laterallyand verticaly offset from the focus to project a passing beam downwardlyand to the right hand side of the road; a substantialy transparent frontcover plate for said headlight; and means to connect said front coverand said reflector.

4. In a headlight, the combination of a substantially concave reflectingsurface, said reflector comprising a plurality of vertically arrangedsections having a parabolic central zone, each section beingtransversely curved, the amount of such curvature varying continuouslyfrom the bottom to the top of each of said vertically arranged sections,and the varying transverse curvature gradually disappearing at theparabolic central zone and fanning out at both sides thereof so as toproject light downwardly and laterally; a plurality of horizontallyarranged elongated flla= ments, one located substantially at the focusand symmetrically arranged with respect thereto; the other filamentbeing horizontally elongated and located above the focus and in avertical plane passing therethrough, but horizontally offset from avertical line through said focus to project a passing beam downwardlyand to the right hand side of the road.

5. In a headlamp the combination of a concave reflecting surface; saidreflecting surface having a main transverse central section of trueparabolic contour connected to modified upper and lower sections whichare formed with a plurality of vertically disposed flutes, each flutehaving a variable transverse curvature throughout its length whichgradually flattens out to conform substantially to the parabolic contourof the central section Without forming transition terminal surfaces soas to project the light downwardly and laterally; a plurality ofhorizontally arranged elongated filaments, one located substantialy atthe focus of the parabolic section and symmetrically disposed withrespect thereto; the other filament being horizontally elongated butlaterally and vertically offset from the focus to project a passing beamdownwardly and to the right hand side of the road; a substantially plainglass front cover plate for said headlight; and means to connect saidfront cover and said reflector.

6. In a headlamp the combination of a concave reflecting surface; saidreflecting surface having main transverse central and lateral sectionsof true parabolic contour and top and bottom sections formed with aplurality of vertically disposed narrow transversely curved zones, thetransverse curvature of each zone gradualy flattened out to conformsubstantialy to the parabolic contour of the main sections withoutforming transition terminal surfaces and having maximum curvature at therim of the reflecting surface so as to project light downwardly andlaterally; a plurality of horizontally arranged elongated filaments, onelocated substantially at the focus of the parabolic sections andsymmetrically disposed with respect thereto; the other filament beinghorizontally elongated but laterally and vertically offset from thefocus to project a passing beam downwardly and to the right hand side ofthe road; a substantially plain glass front cover plate for saidheadlight; and means to connect said front cover and said reflector. GUYH. COULTER.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS Taylor Jan. 3, 1939

